PALEOTEMPERATURES DERIVED FROM LONG CHAIN ALKENONES IN EAST GREENLAND LACUSTRINE SEDIMENT AND THE IMPLICATIONS FOR HOLOCENE PALEOCLIMATE

An exploration of lacustrine sediment from three lakes around 70.5º north latitude in East Greenland revealed biomarkers known as Long Chain Alkenones (LCAs) in one lake that can be used for reconstructing paleo lake temperatures. Although these LCAs were only found in Snoopy Lake, they can provide information on the paleoclimtaic conditions of this region. A comparison of this record with other alkenone records from West Greenland could contribute to a more complete understanding of Holocene climatic trends in the Arctic.

This study reports a sequence of lacustrine paleotemperatures from the Scoresby Sund region of East Greenland. C37 LCAs were analyzed using the alkenone unsaturation index Uk37 along with published lacustrine alkenone temperature calibrations. Although each temperature calibration provided different absolute temperatures, the climatic trends remained the same throughout the entire sequence. The samples yielded the coldest temperature at 9700 YBP and the warmest temperature around 7300 YBP. The temperature reconstruction from this core revealed cold periods around 9700 YBP and 5600 YBP. A warm period was observed around 7300 YBP, which could correlate to the Mid-Holocene Climate Optimum. A 2.5ºC drop in temperature was registered between 7300 and 6600 YBP and a gentle warming trend appears from 5600 YBP to modern time. This record reports trends that contradict other published Holocene records, but if validated, our results could have implications for climate trends at a much smaller regional scale than previously reported for the Holocene.